Re: [PATCH V3 1/6] dmaengine: zynqmp_dma: Fix PM usage count handling in probe error path

On Mon, Aug 10, 2026 at 03:34:47PM +0530, Golla Nagendra wrote:
> When pm_runtime_resume_and_get() succeeds during probe, it increments
> the usage count and enables clocks. If a later step (e.g., channel
> probe) fails, the error path only called pm_runtime_disable() without
> a matching pm_runtime_put_sync(), leaking the reference and the clock
> enable.
>
> Add an else branch to drop the usage count acquired by
> pm_runtime_resume_and_get() when runtime PM is still enabled, letting
> the PM core suspend/disable clocks on the success-then-later-failure
> path.
>
> Fixes: 64c6f7da8c2c ("dmaengine: zynqmp_dma: Add runtime pm support")
> Signed-off-by: Golla Nagendra <[email protected]>
> ---
> Changes in V3:
> - New patch: split from V2 2/3 per Frank Li's review to keep the PM usage
>   count fix separate from the per-channel reset changes
> ---
>  drivers/dma/xilinx/zynqmp_dma.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
> index f6a812e49ddc..87986f65d24c 100644
> --- a/drivers/dma/xilinx/zynqmp_dma.c
> +++ b/drivers/dma/xilinx/zynqmp_dma.c
> @@ -1152,6 +1152,8 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
>  err_disable_pm:
>  	if (!pm_runtime_enabled(zdev->dev))

You just enable runtime pm above few lines.  Is it for CONFIG_PM?

You should check return value of pm_runtime_enable(), or change to use

devm_pm_runtime_enable().

if devm_runtime_enable() failure, you can direct return. Need check
pm_runtime_enabled() here again.

>  		zynqmp_dma_runtime_suspend(zdev->dev);
> +	else
> +		pm_runtime_put_sync(zdev->dev);

This one suggest use PM acquire to fix this.

Frank

>  	pm_runtime_disable(zdev->dev);
>  	return ret;
>  }
> --
> 2.43.7
>